The persistent underrepresentation of female and minority students in Science, Technology, Engineering, and Mathematics (STEM) fields remains a critical challenge in American education. This study examines the effectiveness of growth mindset interventions in improving math and science self-efficacy among female and underrepresented minority high school students. Through a comprehensive review of empirical research conducted between 2013 and 2025, this study synthesizes findings from diverse intervention programs and explores the mechanisms through which growth mindset beliefs influence STEM engagement and persistence. Results indicate that well-designed growth mindset interventions can significantly enhance self-efficacy, reduce stereotype threat, and narrow achievement gaps for female and minority students in STEM disciplines. The study reveals that interventions incorporating teacher training, peer support mechanisms, and culturally responsive practices demonstrate the strongest effects on student outcomes. However, effectiveness varies based on implementation fidelity, institutional support, and the integration of complementary interventions addressing systemic barriers. The findings underscore the importance of creating growth-oriented classroom cultures that combine individual mindset development with structural changes in educational environments. This research contributes to educational policy by providing evidence-based recommendations for designing and implementing interventions that promote equity and inclusion in STEM education.